Clamping latch



Oct. 2, 1951 A. F. ALEXANDER CLAMPING LATCH Filed Nov. 15, 1947 INVENTOR.

Patented Oct. 2, 19 51 UNITED STATES PATENT OFFICE CLAMPING LATCH Arthur F. Alexander, Cleveland, Ohio Application November 15, 1947, Serial No. 786,194

2 Claims. 1

This invention relates to improvements in clamping latches, that is to say latches of the type that are designed to draw together and seal the joint between two elements and maintain the elements in such clamped relation.

.One of the objects of the invention is the provision. of a simple and readily operated latch of the character stated.

Another object is the provision of such a latch for horizontally hinged closures, wherein the latch rides into position to be clamped when the lid or other upper element of the closure is lowered to closing position, and similarly rides clear of the actuator when the lid is raised.

Other objects and features of novelty will appear as I proceed with the description of that embodiment of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawing, in which Fig. 1 is a fragmental perspective view of a box or the like equipped with a clamping latch constructed in accordance with the invention.

Fig. 2 is a fragmental side elevational view showing the latch in clamping position.

Fig. 3 is a similar view showing the latch unclamped, and

Fig. 4 is a front elevational view with the latch in clamping position.

In the drawing two elements to be clamped together in sealing relation are indicated at l and II. These elements for example may be a box H and a lid hinged together at the side remote from the latch. A handle 12 would usually be provided for enabling the operator to swing the upper element In to open position or lower it to closed position.

The complete latch assembly includes a bracket or integral boss l3 to be carried by the element [0. In this bracket or boss there is mounted a pivot M, from which hangs a latch arm [5. In the illustrated case this latch arm is channel shaped in cross-section with the interior of the channel facing inward. Concavities I6 are formed in the flanges of the channel, and at the lower ends of these concavities each flange is provided with a rounded hook IT. The lower extremities of the two flanges are formed with curved cam surfaces 18. The center of gravity of the latch arm is such that the arm tends to assume the position of Fig. 3 when it hangs freely from pivot Hi.

The complete latch assembly also includes a bracket or boss 20 to be carried by the element II. This bracket or boss is slightly wider than the latch arm. In it I mount a rock shaft 21,

which also has a bearing in a bracket or boss 22 on element ll. Alaterally extending handle 23 is formed integral with shaft 2|, and projects in an approximately horizontal direction when the latch is in unclamped position shown in Fig. 3 as well as when it is in clamping position shown in Figs. 1 and 2.

The inner end of shaft 2| is rebent to provide an offset portion 24 which is parallel to the shaft proper, and which portion I term an eccentric actuator. When the handle 23 is swung upwardly from the Fig. 2 position to one in which the handle stands slightly beyond vertical position, gravi ty acting upon the handle swings the shaft to the position of Fig. 3 where it is stopped by the eccentric actuator engaging the upper side of the bracket or boss 20.

Operation-Assuming that the parts are in the clamped or sealing position of Fig. 2, if the closure is to be opened the operator grasps handle 23 and swings it upwardly in the counterclockwise direction. Eccentric actuator 24 then runs against the concavities I6 of the latch arm which consequently swings outwardly somewhat upon its pivot 14. As soon as the actuator 25 leaves the hook i1 clamping pressure is relieved. When the handle 23 has been moved upwardly beyond the vertical plane through shaft 2| the operator releases the handle and it falls by gravity into the position of Fig. 3. The operator may then grasp the handle 12 and swing the element l0 upwardly to open position.

During the opening movement the rounded ends of hooks I! bear against the lower cam surface of bracket or boss 20 and thus clear the same. They then ride over the upper cam surface of the boss until they strike the round surface of the eccentric actuator 24, over which they ride freely. As soon as they clear the actuator 2 the latch swings inwardly, or clockwise, until stopped by a projection 25 on the boss [3. A series of positions occupied by the latch arm during the raising of element I!) are shown in broken lines in Fig. 3.

When the element II] is lowered to closing position the latch arm moves downwardly through the positions shown in Fig. 3 due to th shape of the cam surfaces Is on the latch, which ride over the eccentric actuator 24 and the upper inclined surface of boss 20. When the latch reaches the full line position of that figure the operator grasps handle 23 and swings it clockwise through an angle slightly greater than During this movement the actuator 24 swings latch arm l5 outwardly to some extent, but as the actuator moves downwardly from its outermost position the concavities l6 follow the actuator inwardly until the latter engages behind the hook I! somewhat to the right of the plane through pivot I 4 and shaft 2|. Downward pressure on handle 23 then exerts a pull through actuator 24 against the hook l1, thereby effecting a tight closure or seal of the joint between the elements It] and II. At the same time the eccentric actuator 24 moves inwardly over dead center, that; is beyond the plane through pivot I4 and shaft 2| and into engagement with the lower inclined surface of boss, 20, thereby locking the elements in closed and clamped relation.

As will be apparent from the foregoing the operator does not need to touch the latch arm i8 when he opens or closes the elements; (q and it, Hence he can use one hand to lift or lower the element I by means of handle l2, and the other hand to operate the actuator 24 by means of handle 23.

Having thus described my invention, I claim:

1. A clamping latch comprisinga pivot mounted horizontally on the upper of two ele-. ments to be clamped together, said pivot being spaced horizontally a substantial distance away from said element, a shaft journaled on the lower element parallel to said pivot and in substantially the same vertical plane, a latch ar-m disposed outwardly of said shaft the upper end of which hangs on said pivot, said arm having a hook on its inner lower end projecting below and inwardly of said shaft when the upper element engages the lower element, an offset actuator on said shaft inwardly of said arm adapted to engage said hook for exerting a downward pull on said arm, stop means for limiting the downward and inward movement of said actuator beneath said shaft to a position slightly inward of said vertical plane, stop means for limitng the upward and inward movement of said actuator above said shaft to a position slightly inward of said vertical plane, an operating handle on said shaft adapted to overbalance said actuator in either position for holding it against one of said stop means, and cam 4 surfaces at the lower end of said latch arm for deflecting the arm outwardly as it engages the actuator in the upper position of the latter during either upward or downward movement of the latch arm.

2. A clamping latch comprising a pivot mounted horizontally on the upper of two elements to be clamped together, said pivot being paced, b t qetel ubstan ial d s a c away from; said element, a boss mounted on the lower element beneath said pivot, a shaft journaled in said boss parallel to said pivot and in substantially the same vertical plane, a latch arm disposed outweirdly of said shaft, the upper end of which hangs on said pivot, said arm having a hook on its inner lower end projecting below said boss inwardly oi said shaft when the upper element engages the lower element, said shaft having an offset rebent extremity I extending in front of said boss adapted to engage said hook for exerting a downward pull on said arm, said boss constituting stop means for said rebent extremity when swung upwardly or downwardly slightly b.e-, yond said vertical plane, an operating handle on said shaft adapted to overbalance said offset ex: tremity in either position for holding it against said boss, and cam surfaces at the lower end of said latch arm for deflecting it outwardly as it engages the said rebent extremity in the upper position of the latter during either upward or downward movement of the latch arm.

ARTHUR 1i. ALEXANDER.

REFERENC S, CITED The following references are file of this patent:-

UNITED sure PATENTS of record in the 

